Variations in the profiles of Alpha Camelopardalis' spectral lines are caused by fluctuations in the photosphere and stellar wind. This may be caused by non-radial pulsations. The absorption lines in the optical spectrum show radial velocity variations, although there is significant uncertainty about the period. Estimates range from a period as low as 0.36 days up to 2.93 days. The stellar wind from this star is not smooth and continuous, but instead shows a behavior indicating clumping at both large and small scales.[10] This star is losing mass rapidly through its stellar wind at a rate of approximately 6.3 × 10−6solar masses per year,[5] or the equivalent of the mass of the Sun every 160,000 years.
In 1968, this star was classified as a spectroscopic binary, indicating that it has an orbiting stellar companion with a period of 3.68 days and an orbital eccentricity of 0.45. Subsequent studies refined the period to 3.24 days. However, in 2006 it was recognized that the changes in the spectrum were probably the result of changes in the atmosphere or stellar wind, so it is more likely a single star.[11] Speckle interferometry observations with the 3.67 m Advanced Electro Optical System Telescope at the Haleakala Observatory failed to detect a secondary component.[12]
In 1961, based on the criteria that the proper motion of this star indicates a space velocity of greater than 30 km/s,[13] Alpha Camelopardalis was suggested as a candidate runaway star that had been ejected from the cluster NGC 1502. This was based upon the kinematic properties of the star and cluster, as well as the location of this star at a high galactic latitude in an area otherwise lacking in stellar associations. Over the course of a million years, this star should have moved only 1.4° across the sky, while it was estimated as being only two million years old.[7]
Runaway stars such as this with a stellar wind that is moving at supersonic velocity through the interstellar medium have their wind confined by a bow shock due to ram pressure. The dust in this bow shock can be detected using an infrared telescope.[14] Just such a bow shock was observed with NASA's Wide-field Infrared Survey Explorer, or WISE. The star is traveling at a rate of somewhere between 680 and 4,200 kilometers per second: between 1.5 and 9.4 million mph.[15]
^ abcdevan Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
^ abcdDucati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
^Sota, A.; Maíz Apellániz, J.; Walborn, N. R.; Alfaro, E. J.; Barbá, R. H.; Morrell, N. I.; Gamen, R. C.; Arias, J. I. (2011). "The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-violet at R ~ 2500". The Astrophysical Journal Supplement. 193 (2): 24. arXiv:1101.4002. Bibcode:2011ApJS..193...24S. doi:10.1088/0067-0049/193/2/24. S2CID 119248206.
^ abMarkova, N. (April 2002), "Spectral variability of luminous early type stars . II. Supergiant alpha Camelopardalis", Astronomy and Astrophysics, 385 (2): 479–487, Bibcode:2002A&A...385..479M, doi:10.1051/0004-6361:20020153 See Table 1.
^Repolust, T.; Puls, J.; Herrero, A. (2004). "Stellar and wind parameters of Galactic O-stars. The influence of line-blocking/blanketing". Astronomy and Astrophysics. 415 (1): 349–376. Bibcode:2004A&A...415..349R. doi:10.1051/0004-6361:20034594.
^ abBlaauw, A. (May 1961), "On the origin of the O- and B-type stars with high velocities (the "run-away" stars), and some related problems", Bulletin of the Astronomical Institutes of the Netherlands, 15: 265, Bibcode:1961BAN....15..265B
^Aveni, A. F.; Hunter, H. J., Jr. (October 1967), "Observational studies relating to star formation. I.", Astronomical Journal, 72: 1019–1027, Bibcode:1967AJ.....72.1019A, doi:10.1086/110378{{citation}}: CS1 maint: multiple names: authors list (link)
^Prinja, R. K.; et al. (October 2006), "The superimposed photospheric and stellar wind variability of the O-type supergiant α Camelopardalis", Astronomy and Astrophysics, 457 (3): 987–994, arXiv:astro-ph/0606720, Bibcode:2006A&A...457..987P, doi:10.1051/0004-6361:20065114, S2CID 14180933
^McSwain, M. Virginia; et al. (January 2007), "A Spectroscopic Study of Field and Runaway OB Stars", The Astrophysical Journal, 655 (1): 473–483, arXiv:astro-ph/0608270, Bibcode:2007ApJ...655..473M, doi:10.1086/509914, S2CID 18121243
^Turner, Nils H.; et al. (August 2008), "Adaptive Optics Photometry and Astrometry of Binary Stars. III. a Faint Companion Search of O-Star Systems", The Astronomical Journal, 136 (2): 554–565, arXiv:0805.3162, Bibcode:2008AJ....136..554T, doi:10.1088/0004-6256/136/2/554, S2CID 15819352
^Gies, D. R. (July 1987), "The kinematical and binary properties of association and field O stars", Astrophysical Journal Supplement Series, 64: 545–563, Bibcode:1987ApJS...64..545G, doi:10.1086/191208
^Noriega-Crespo, Alberto; van Buren, Dave; Dgani, Ruth (February 1997), "Bow Shocks Around Runaway Stars.III.The High Resolution Maps", Astronomical Journal, 113: 780–786, Bibcode:1997AJ....113..780N, doi:10.1086/118298
^(in Chinese)中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN978-986-7332-25-7.
^(in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 11 日
^English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name 2008-09-24 at the Wayback Machine, Hong Kong Space Museum. Accessed on line November 23, 2010
^ abAllen, Richard Hinckley (1899), "Star-names and their meanings", New York, G. E. Stechert: 106, Bibcode:1899sntm.book.....A, retrieved 2011-12-24
Image of the constellational matrix formed by viewing the constellational lines at 16,000 light-years from the sun. Spike at the left is Alpha Camelopardalis.
October 20, 2023
alpha, camelopardalis, latinized, from, camelopardalis, star, northern, constellation, camelopardalis, with, apparent, visual, magnitude, third, brightest, star, this, very, prominent, circumpolar, constellation, first, second, brightest, stars, being, beta, c. Alpha Camelopardalis Latinized from a Camelopardalis is a star in the northern constellation of Camelopardalis With an apparent visual magnitude of 4 3 it is the third brightest star in this not very prominent circumpolar constellation the first and second brightest stars being Beta Camelopardalis and CS Camelopardalis respectively It is the farthest constellational star with a distance of approximately 6 000 light years from Earth based on parallax measurements Alpha CamelopardalisLocation of a Camelopardalis circled Observation dataEpoch J2000 0 Equinox J2000 0 ICRS Constellation CamelopardalisRight ascension 04h 54m 03 01040s 1 Declination 66 20 33 6365 1 Apparent magnitude V 4 29 2 CharacteristicsSpectral type O9Ia 3 U B color index 0 87 2 B V color index 0 05 2 R I color index 0 00 2 AstrometryRadial velocity Rv 6 1 4 km sProper motion m RA 0 13 1 mas yr Dec 6 89 1 mas yrParallax p 0 52 0 19 mas 1 Distanceapprox 6 000 ly approx 1 900 pc Absolute magnitude MV 7 1 5 Details 6 Mass37 6 M Radius32 5 R Luminosity676 000 L Surface gravity log g 2 97 cgsTemperature29 000 KRotational velocity v sin i 100 km sAge 2 7 MyrOther designationsa Cam Alpha Camelopardalis Alpha Cam 9 Camelopardalis 9 Cam BD 66 358 FK5 178 GC 5924 HD 30614 HIP 22783 HR 1542 SAO 13298 PPM 15047 WDS J04541 6621 IRAS 04490 6615Database referencesSIMBADdata Contents 1 Description 2 Chinese name 3 References 4 External linksDescription EditAlpha Camelopardalis has a stellar classification of O9 Ia with the Ia indicating that it is an O type luminous supergiant It is a massive star with 37 6 times the mass of the Sun and 32 5 times the Sun s radius The effective temperature of the outer envelope is 29 000 K much hotter than the Sun s effective temperature of 5 778 K giving it the characteristic blue hue of an O type star 8 It is emitting 676 000 times the luminosity of the Sun and is a weak X ray emitter 9 Variations in the profiles of Alpha Camelopardalis spectral lines are caused by fluctuations in the photosphere and stellar wind This may be caused by non radial pulsations The absorption lines in the optical spectrum show radial velocity variations although there is significant uncertainty about the period Estimates range from a period as low as 0 36 days up to 2 93 days The stellar wind from this star is not smooth and continuous but instead shows a behavior indicating clumping at both large and small scales 10 This star is losing mass rapidly through its stellar wind at a rate of approximately 6 3 10 6 solar masses per year 5 or the equivalent of the mass of the Sun every 160 000 years In 1968 this star was classified as a spectroscopic binary indicating that it has an orbiting stellar companion with a period of 3 68 days and an orbital eccentricity of 0 45 Subsequent studies refined the period to 3 24 days However in 2006 it was recognized that the changes in the spectrum were probably the result of changes in the atmosphere or stellar wind so it is more likely a single star 11 Speckle interferometry observations with the 3 67 m Advanced Electro Optical System Telescope at the Haleakala Observatory failed to detect a secondary component 12 In 1961 based on the criteria that the proper motion of this star indicates a space velocity of greater than 30 km s 13 Alpha Camelopardalis was suggested as a candidate runaway star that had been ejected from the cluster NGC 1502 This was based upon the kinematic properties of the star and cluster as well as the location of this star at a high galactic latitude in an area otherwise lacking in stellar associations Over the course of a million years this star should have moved only 1 4 across the sky while it was estimated as being only two million years old 7 Runaway stars such as this with a stellar wind that is moving at supersonic velocity through the interstellar medium have their wind confined by a bow shock due to ram pressure The dust in this bow shock can be detected using an infrared telescope 14 Just such a bow shock was observed with NASA s Wide field Infrared Survey Explorer or WISE The star is traveling at a rate of somewhere between 680 and 4 200 kilometers per second between 1 5 and 9 4 million mph 15 Chinese name EditIn Chinese 紫微右垣 Zǐ Wei You Yuan meaning Right Wall of Purple Forbidden Enclosure refers to an asterism consisting of a Camelopardalis a Draconis k Draconis l Draconis 24 Ursae Majoris 43 Camelopardalis and BK Camelopardalis 16 Consequently the Chinese name for a Camelopardalis itself is 紫微右垣六 Zǐ Wei You Yuan liu English the Sixth Star of Right Wall of Purple Forbidden Enclosure 17 representing 少衛 Shǎowei meaning Second Imperial Guard 18 19 少衛 Shǎowei is westernized into Shaou Wei by R H Allen the meaning is Minor Guard but it is not clearly designated 19 References Edit a b c d e van Leeuwen F November 2007 Validation of the new Hipparcos reduction Astronomy and Astrophysics 474 2 653 664 arXiv 0708 1752 Bibcode 2007A amp A 474 653V doi 10 1051 0004 6361 20078357 S2CID 18759600 a b c d Ducati J R 2002 VizieR Online Data Catalog Catalogue of Stellar Photometry in Johnson s 11 color system CDS ADC Collection of Electronic Catalogues 2237 Bibcode 2002yCat 2237 0D Sota A Maiz Apellaniz J Walborn N R Alfaro E J Barba R H Morrell N I Gamen R C Arias J I 2011 The Galactic O Star Spectroscopic Survey I Classification System and Bright Northern Stars in the Blue violet at R 2500 The Astrophysical Journal Supplement 193 2 24 arXiv 1101 4002 Bibcode 2011ApJS 193 24S doi 10 1088 0067 0049 193 2 24 S2CID 119248206 Wilson Ralph Elmer 1953 General catalogue of stellar radial velocities Washington Carnegie Institution of Washington Bibcode 1953GCRV C 0W a b Markova N April 2002 Spectral variability of luminous early type stars II Supergiant alpha Camelopardalis Astronomy and Astrophysics 385 2 479 487 Bibcode 2002A amp A 385 479M doi 10 1051 0004 6361 20020153 See Table 1 Repolust T Puls J Herrero A 2004 Stellar and wind parameters of Galactic O stars The influence of line blocking blanketing Astronomy and Astrophysics 415 1 349 376 Bibcode 2004A amp A 415 349R doi 10 1051 0004 6361 20034594 a b Blaauw A May 1961 On the origin of the O and B type stars with high velocities the run away stars and some related problems Bulletin of the Astronomical Institutes of the Netherlands 15 265 Bibcode 1961BAN 15 265B The Colour of Stars Australia Telescope Outreach and Education Commonwealth Scientific and Industrial Research Organisation December 21 2004 archived from the original on March 18 2012 retrieved 2012 01 16 Aveni A F Hunter H J Jr October 1967 Observational studies relating to star formation I Astronomical Journal 72 1019 1027 Bibcode 1967AJ 72 1019A doi 10 1086 110378 a href Template Citation html title Template Citation citation a CS1 maint multiple names authors list link Prinja R K et al October 2006 The superimposed photospheric and stellar wind variability of the O type supergiant a Camelopardalis Astronomy and Astrophysics 457 3 987 994 arXiv astro ph 0606720 Bibcode 2006A amp A 457 987P doi 10 1051 0004 6361 20065114 S2CID 14180933 McSwain M Virginia et al January 2007 A Spectroscopic Study of Field and Runaway OB Stars The Astrophysical Journal 655 1 473 483 arXiv astro ph 0608270 Bibcode 2007ApJ 655 473M doi 10 1086 509914 S2CID 18121243 Turner Nils H et al August 2008 Adaptive Optics Photometry and Astrometry of Binary Stars III a Faint Companion Search of O Star Systems The Astronomical Journal 136 2 554 565 arXiv 0805 3162 Bibcode 2008AJ 136 554T doi 10 1088 0004 6256 136 2 554 S2CID 15819352 Gies D R July 1987 The kinematical and binary properties of association and field O stars Astrophysical Journal Supplement Series 64 545 563 Bibcode 1987ApJS 64 545G doi 10 1086 191208 Noriega Crespo Alberto van Buren Dave Dgani Ruth February 1997 Bow Shocks Around Runaway Stars III The High Resolution Maps Astronomical Journal 113 780 786 Bibcode 1997AJ 113 780N doi 10 1086 118298 Clavin Whitney March 11 2011 Speed demon creates a shock physorg retrieved 2011 12 24 in Chinese 中國星座神話 written by 陳久金 Published by 台灣書房出版有限公司 2005 ISBN 978 986 7332 25 7 in Chinese AEEA Activities of Exhibition and Education in Astronomy 天文教育資訊網 2006 年 6 月 11 日 English Chinese Glossary of Chinese Star Regions Asterisms and Star Name Archived 2008 09 24 at the Wayback Machine Hong Kong Space Museum Accessed on line November 23 2010 a b Allen Richard Hinckley 1899 Star names and their meanings New York G E Stechert 106 Bibcode 1899sntm book A retrieved 2011 12 24External links EditHR 1542 entry in the Bright Star Catalogue Alpha Camelopardalis in Aladin Image of the constellational matrix formed by viewing the constellational lines at 16 000 light years from the sun Spike at the left is Alpha Camelopardalis Retrieved from https en wikipedia org w index php title Alpha Camelopardalis amp oldid 1170139218, wikipedia, wiki, book, books, library,
